Ejstbico eosenzi



ENRICO ROSENZI, OF PITTSBURG, PENNSYLVANIA.

MANUFACTURE OF OBSIDIAN LOOKING-GLASSES.

SPECIFICATION forming part of Letters Patent No. 309,741, dated December23, 1884-.

Application filed May 18, 1884. (Specimens) To all whom it may concern;

Be it known that I, ENRIoo RosENzI, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements in theManufacture of Ohsidian LookingGlasses, of which the following is aspecification.

My invention relates to an improvement in the manufacture of obsidianlooking-glasses; and it consists in the employment and use of ferroline,a material of Whichthe composition was invented by myself, and isprotected by Letters PatentNo. 244,486, granted to me on July 19, 1881,instead of obsidian, used by the Romans and Greeks in former ages forlooking-glasses and reflectors on astronomical instruments.

The obsidian is known to be a kind of glass, produced by volcanoes, andcomposed of ingredients similar to those employed in making andcompounding ferroline. As described in the said patent, the componentparts of ferroline are soda, silex, ashes, lime, magnesia, boraX, andarsenic, and the same have been found in obsidian. The high degree ofpolish of which the ferroline is susceptible qualifies it above othermaterialsfor lookingglasses, and its deep black color gives it apcculiarly attractive appearance. The mass ob tained by the properintermixturc of the ingredients named is cast or blown into plates ofany desirable form and thickness-flat, concave, or convexand polishedand framed to fit the place it may be destined to occupy.

The advantage gained by substituting ferroline for obsidian consists inits cheapness over the volcanic production, and in its adaptability toall forms and sizes. The perfection and beauty of these looking-glassescan only be appreciated by examination. Nothing of the kind has everbeen offered to the public. The reflections are as clear and distinct asseen in the brightest glass mirrors, but subdued by a tint that givesthe reflected image a peculiar charm. Ferroline may also be used forreflectors, and will be found of great brilliancy, but deprived of theglare reflected by metal, so offensive and injurious to the eye.

Having thus described my invention, I claim The employment of ferrolinein the manufacture of obsidian looking-glasses and reflectors,substantially as described. I

In testimony whereof I affix my signature in presence of two witnesses.

ENBIGO ROSENZI. Vitnesses:

T. F. LEHMANN, CHAS. F. MoKENNA.

